<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }
    .mask {
      height: 100vh;
      background-color: #000;
      color: #fff;
      display: flex;
      justify-content: center;
      align-items: center;
      font-size: 150px;
    }
    @keyframes blurOut {
      0% {
        opacity: 1;
        filter: blur(0px);
        transform: scale(1);
      }
      30% {
        opacity: 0;
        filter: blur(20px);
        transform: scale(2);
      }
      60%, 100% {
        opacity: 1;
        filter: blur(0px);
        transform: scale(1);
      }
    } 
    .mask span {
      text-shadow: 2px 2px 4px rgba(255, 255, 255, 0.7);
      display: inline-block;
      animation: blurOut 4s ease-in-out infinite;
      animation-delay: calc(.2s*var(--i));
    }
  </style>
</head>
<body>
<div class="mask">
  <span style="--i:1">W</span>
  <span style="--i:2">E</span>
  <span style="--i:3">L</span>
  <span style="--i:4">C</span>
  <span style="--i:5">O</span>
  <span style="--i:6">M</span>
  <span style="--i:7">E</span>
</div>
</body>
</html>